Question

我继承了一个JBOSS 4.2.3.GA。ear项目，如果我使用JDK 7u45构建它，所有内容都会加载并运行正常，但无法加载＆amp;如果我使用任何更新的JDK 7（例如7u76,7u79,7u80）构建它，请在JBoss Bootstrap中尽早运行。

JBOSS服务器本身在Java 1.7.0_45上运行。

失败的记录原因是实际存在的类的ClassNofFoundException（即使是失败的.ear）：

log4j:ERROR Could not create the Layout. Reported error follows.
java.lang.ClassNotFoundException: dbs.common.logger.CsvLayout
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:190)
        at org.apache.log4j.helpers.Loader.loadClass(Loader.java:178)
        at org.apache.log4j.xml.DOMConfigurator.parseLayout(DOMConfigurator.java:555)
        at org.apache.log4j.xml.DOMConfigurator.parseAppender(DOMConfigurator.java:269)
        at org.apache.log4j.xml.DOMConfigurator.findAppenderByName(DOMConfigurator.java:176)
        at org.apache.log4j.xml.DOMConfigurator.findAppenderByReference(DOMConfigurator.java:191)
        at org.apache.log4j.xml.DOMConfigurator.parseChildrenOfLoggerElement(DOMConfigurator.java:523)
        at org.apache.log4j.xml.DOMConfigurator.parseCategory(DOMConfigurator.java:436)
        at org.apache.log4j.xml.DOMConfigurator.parse(DOMConfigurator.java:999)
        at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:867)
        at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:773)
        at org.apache.log4j.xml.DOMConfigurator.configure(DOMConfigurator.java:901)
        at org.jboss.logging.Log4jService$URLWatchTimerTask.reconfigure(Log4jService.java:643)
        at org.jboss.logging.Log4jService$URLWatchTimerTask.run(Log4jService.java:582)
        at org.jboss.logging.Log4jService.setup(Log4jService.java:460)
        at org.jboss.logging.Log4jService.createService(Log4jService.java:476)
        at org.jboss.system.ServiceMBeanSupport.jbossInternalCreate(ServiceMBeanSupport.java:260)
        at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:243)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.system.ServiceController$ServiceProxy.invoke(ServiceController.java:978)
        at com.sun.proxy.$Proxy0.create(Unknown Source)
        at org.jboss.system.ServiceController.create(ServiceController.java:330)
        at org.jboss.system.ServiceController.create(ServiceController.java:273)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:86)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at com.sun.proxy.$Proxy4.create(Unknown Source)
        at org.jboss.deployment.SARDeployer.create(SARDeployer.java:260)
        at org.jboss.deployment.MainDeployer.create(MainDeployer.java:969)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:818)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:782)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:766)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at com.sun.proxy.$Proxy5.deploy(Unknown Source)
        at org.jboss.system.server.ServerImpl.doStart(ServerImpl.java:482)
        at org.jboss.system.server.ServerImpl.start(ServerImpl.java:362)
        at org.jboss.Main.boot(Main.java:200)
        at org.jboss.Main$1.run(Main.java:508)
        at java.lang.Thread.run(Thread.java:744)

通常，我很容易找到ClassNofFoundException的real原因，但这次我感到困惑，考虑到以下事实：

.ear的整个环境（包括 CLASSPATH ！）相同。
前面提到的“未找到的类”dbs.common.logger.CsvLayout 位于 common.jar文件中，该路径与应该完全相同。
构建中没有任何错误。
在其他人的开发工作站（同样的Eclipse等）构建.ear与JDK 7u79（即稍后更新比7u45），导致.ear正确加载并运行（在同一台服务器上）和环境）。

什么可以解释这样的ClassNofFoundException？

我错过了什么？

更新比较工作和不工作的common.jar文件之间的“未找到”CsvLayout.class，表明class file format的major_version存在差异。工作的有0x33（Java SE 7），失败有0x34（Java SE 8）。

我一直小心翼翼地始终使用仅限jre7的执行环境。那0x34怎么潜入？

Answer 1

问题来自于库 common.jar ：是使用java 8构建的，而没有指定目标类文件版本，因此生成了带有java 8类文件版本的jar文件。 / p>

要使用Java 8构建Java 7类文件，您需要

纯java编译：添加目标选项javac -target 1.7 <javafile>
maven：添加属性<maven.compiler.target>1.7</maven.compiler.target>
ant：将<property name="ant.build.javac.source" value="1.7"/> <property name="ant.build.javac.target" value="1.7"/>添加到build.xml

ClassNotFoundException仅依赖于JDK7更新版本？

1 个答案: